/Engine/Plugins/VirtualProduction/DMX/DMXEngine/Source/DMXBlueprintGraph/Public/K2Node_CastPatchToType.h
What we need here is to serialize this node in both the parent and grand parent ways, because one will serialize the user defined pins (since this extends fromUK2Node_EditablePinBase), but by doing only the parent serialization, it'll skip the serialization of the structs we have as IN pins (UE bug?). However, the grandparent class serializes it correctly. This method basically merges both serializations so it works as expected
virtual void Serialize ( [FArchive](API\Runtime\Core\Serialization\FArchive) & Ar )